U.S. Pat. No. 4,603,675 discloses a method and an arrangement for controlling the drive power of a motor vehicle. Here, a driver command is detected on the basis of the position of an operator-controlled element actuated by the driver and a power-output element is controlled to a position pregiven by the driver command by means of a position control. The power-output element influences the power of the drive unit. The detected positions of the operator-controlled element and of the power-output element are compared to each other with respect to impermissible deviations in order to improve the operational reliability of this system which supplies fuel via an electric circuit.
If the position of the operator-controlled element and the position of the power-output element depart impermissibly from each other and if the power-output element is significantly further open than the position set by the driver command, then a fault in the control system is recognized and, if required, countermeasures are initiated. The precondition for a procedure of this kind is that a fixed relationship between driver command or position of the operator-controlled element and the position of the power-output element is present for normal function of the system and, if required, in the context of the permissible tolerance. The known procedure cannot be satisfactorily utilized in systems where additional influences are provided which even for normal operation actuate the power-output element especially in the direction of increased power with respect to the driver command present.